Process of chlorinating 1,1-dichlorpropene-1



Patented Nov. 2,1937

UNITED STAT-ES V PROCESS OF CHLORINATING I Ll-DICHLORPROPENE-l Oliver W.Cass, Niagara, Falls, N. Y., assignor to E. I. du Pont de Nemours &Company, Wilmington, Del., a corporation of Delaware No Drawing.Application May 13, 1935, Serial No. 21,301

6 Claims. (Cl; 260-162) This application relates to chlorinatedproducts, more particularly chlorinated propane, and methods ofmanufacturing these compounds. More specifically it relates to thepreparation of 5 1,1,1,2-tetrachlorpropane, CH3.CHC1.CC13, by

chlorination of 1,1-dichlorpropene-1,

' CH3.CH=CC12 10 The preparation of 1,1-dichlorpropene-1 is disclosed inmy co-pending application Ser. No.

21,300, filed May 13, 1935. This compound, which,

' order to prepare the saturated chlorinated derivative,1,1,1,2-tetrachlorpropane, a liquid phase re- 20 action in which thechlorine is added in the cold has been found most effective. Achlorination catalyst such as ferric chloride, FeCla, may be used,although a catalyst is not absolutely essential and the reactionproceeds without it though at a relatively low rate of speed. Otherchlorination catalysts such as iodine, sulfur, antimony trichloride andaluminum chloride may also be used. The exposure of the reactionproducts or the reaction mixture to the action of light is undesirablesince it results in various undesirable by-products.

The maintenance of too high a temperature may also be undesirablebecause heat possesses, in 35 a very much lower degree, the sameundesirable efiects as light. For this reason, it is preferred that thetemperature be below room temperature or at least withinthe range -30 C.The reaction is exothermic and proceeds rapidly at tem- 40 peratureswithin this range. For the maintenance of a low temperature it isdesirable to provide the reaction vessel with cooling means, such as awater jacket.

When light is excluded and chlorine is passed into' 1,1-dichlorpropene-1in the liquid phase, undesirable isomers are not produced in substantialamounts, the yield of 1,1,1,2-tetrachlorpropane being practicallyquantitative. For convenience, I prefer to carry out the reaction in thepresence of ferric chloride, FeCls, as a chlorination catalyst, since inthis manner the reaction is completed within a relatively short periodof time.

The reaction occurring may be expressed as follows:

As an example of the novel improved process for the manufacture ofchlorinated derivatives the following may be given:

Example 5 666 grams of 1,1-dichlorpropene-1 and 6.6 grams of anhydrousferric chloride were placed in a 1 liter, 3-necked flask equipped with astirrer, an inlet tube for chlorine gas, and a reflux condenser. Theflask was placed in' an ice bath and shielded from the light. Then 411grams of chlorine gas were passed in during a 4 hour reaction period.The reaction product was thoroughly washed with water and then withsodium carbonate solution, dried and distilled. 984 grams.

of 1,1,1,2tetrachlorpropane were secured, which representsa yield of 90%of the theoretical based on the amount of 1,1-dichlorpropene-1 used upin the reaction.

It is to be understood that the various details of temperature and otherconditions described in the foregoing example are to be considered asillustrative and not restrictive. Thus, various changes might be made inthe temperature, amounts, time of reaction, and other conditions whichwould still be within the scope of the invention. For example, whilethemaintenance of a temperature within the range 0-30 C. is desirable inorder that the yield'may be practically quantitative, it is possible tooperate atmore elevated temperatures, if light is excluded, and stillobtain high yields of 1,1,1,2-tetrachlorpropane. Since various changesmay be made in the details of the process without departing from thespirit 7 of the invention, the scope is to be construed solely inaccordance with the appended claims.

I claim: 1. A process for preparing chlorinated derivatives of propanewhich comprises reacting chlo- 40 V rine and 1,1-dichlorpropene-1 in theliquid phase. in the dark at a temperature within the range 0-30 C.

2. A process for preparing chlorinated derivatives of propane whichcomprises reacting chlorine and 1,1-dichlorpropene-1'in the liquid phasein the presence. of a chlorination catalyst and in the substantialabsence of light at a temperature within the range 0-30 C. j Y

3. A process for preparing chlorinated derivatives of propane whichcomprises reacting chlorine and 1,1-dichlorpropene-1 in the liquid phasein the presence of ferric chloride as a catalyst and in the substantialabsence of light at a temperature within the range 0-30 C.

4; A process of preparing 1,1,1,2-tetrachlorpropane which comprisesreacting chlorine with 1,1-dichlorpropene-1 in the liquid phase in thepresence of a chlorination catalyst and in the substantial absence oflight at a temperature within the range 0-30 C.

5. A process for preparing1,1,1,2-tetrachlorpropane which comprisesreacting chlorine with 1,1-dich1orpropene-1 in the liquid phase and in

